One of the proposals made in recent years is a super-wide-angle lens with an angle of view of 180° or more used for a surveillance camera and onboard camera using a solid-state image pickup device (Japanese Unexamined Patent Application Publication No. 2008-276185 and Japanese Unexamined Patent Application Publication No. 2008-292800).
The super-wide-angle lens system disclosed in the Japanese Unexamined Patent Application Publication No. 2008-276185 has a problem that, when used as the onboard camera or others, the unwanted portions such as sky and ground surface are often captured in the direction of the shorter side of the image pickup device, i.e., in the vertical direction, due to its super-wide angle lens structure.
The lens system disclosed in the Japanese Unexamined Patent Application Publication No. 2008-292800 is made up of six lenses, and an increased size of the lens has been the problem of this system.